Sphenopalatine Ganglion Block
Performed by Top Pain Management Doctors in San Antonio, Texas
A nerve block is a treatment option for pain. This treatment involves injecting anesthetic medicine into a group of nerves, called a ganglion, to numb the pain. The sphenopalatine ganglion block is used to treat facial and head pain. The purpose behind performing a sphenopalatine ganglion block is either to diagnose the cause of pain or relieve acute pain. Pain relief may not happen immediately. Conditions that may warrant sphenopalatine ganglion block treatment to relieve pain include:
- Trigeminal neuralgia
- Acute headaches or cluster headaches
- Herpes zoster
- Paroxysmal hemicrania
- Cancer of the head or neck
- Facial pain that is atypical
- Reflex Sympathetic Dystrophy (RSD)
- Complex regional pain syndrome (CRPS)
Other reasons to use sphenopalatine ganglion block:
- The administration of pre- and postoperative anesthesia during oral or maxillofacial surgery
- Vasomotor rhinitis
The sphenopalatine ganglion is a bundle of parasympathetic nerves found in a cavity of the skull named the pterygopalatine fossa, a space located just behind the middle nasal turbinate and in front of the pterygoid canal. This ganglion is no larger than five millimeters in size, covered in connective tissue and mucous membrane about one to one and a half millimeters thick. Nerves emitting from the sphenopalatine ganglion travel to the nasal cavity glands, the lacrimal gland, paranasal sinuses, upper pharynx and palate of the mouth. These nerves do not control facial movement. Though the sphenopalatine ganglion is classified as a parasympathetic ganglion, both sympathetic neurons and somatic sensory afferent branches of the maxillary division of the trigeminal nerve travel through the ganglion. Therefore, signals traveling through the parasympathetic, sympathetic, and somatic sensory afferents can all be interrupted by a sphenopalatine ganglion nerve block. Due to the ganglion’s location, the physician has access to perform a topical or injected nerve block via the transnasal (nose), transoral (mouth), or lateral route. However, the easiest, most commonly chosen route is transnasal.
The patient is instructed to lie down on their back and extend the neck, tilting back the head as if to sniff the air. The physician begins by visually assessing the inside of the nose for blockages such as polyps, tumors, or deviation of the septum. Two percent viscous lidocaine is placed in the nose, and the patient is asked to inhale. The purpose of this medicine is to lubricate the posterior nasal pharynx and decrease discomfort during the injection. For topical application of the sphenopalatine ganglion block, the physician will then place a sterile ten centimeter cotton tipped applicator coated in the nerve blog anesthetic up into the nose slowly, pushing it along the top of the middle turbinate until the posterior wall of the nasopharynx has been reached. It takes 20-30 minutes for the medication to be absorbed into the ganglion, and during this time the applicator must remain in place. Another option is to inject the sphenopalatine ganglion block. This procedure begins with an injection of numbing anesthetic to the patient’s cheek. Using an x-ray for guidance, the physician inserts a small needle through the face and into the location of the ganglion. To verify correct position, fluoroscopy (dye visible using an x-ray) is utilized, and then the nerve block is injected. The sign of an effective nerve block is a marked decrease in pain. This treatment provides only temporary pain relief, but patients who have a documented successful sphenopalatine ganglion block are candidates for neurolysis or radio ablation of the sphenopalatine ganglion for more long-term pain relief.
The sphenopalatine ganglion block procedure is brief in duration, minimally invasive, and proven successful in treating some types of acute and chronic cases of pain experienced in the face and head.
Possible side effects of the sphenopalatine ganglion block procedure:
- Experiencing a bitter taste or minor numb sensation in the mouth as a result of the local anesthetic running down the nasopharynx to the oropharynx
- Epistaxis (nose bleed) from minor abrasions of the mucous membranes during administration of the nerve block
- Feeling lightheaded, which most often goes away within 20-30 minutes of the procedure
Risks to the patient receiving sphenopalatine ganglion block are the same as any procedure in which local anesthetic is administered, including the possibility of an allergic reaction or seizure if the anesthetic is improperly injected into a blood vessel. There is also a risk of infection of the tissues at the injection site.
Sphenopalatine ganglion block is well documented as an effective treatment for acute and chronic head and facial pain. Patients with head and neck cancer can benefit from sphenopalatine ganglion block, which is proven to relieve pain. For example, Varghese et al. (2001) used neurolytic sphenopalatine ganglion block (with endoscopy guidance) to successfully treat 17 of 22 patients with advanced cancer of the head and neck whose cancer-associated pain was not relieved by standard oral medications. These patients continued to report reduced pain at their one month follow up. A study published in 1997 reported that sphenopalatine ganglion block was proven to relieve vasomotor rhinitis in 29 of 30 patients who reported no recurrence of symptoms through the follow up period of 12-20 months. These patients require 3 blocks each week to experience completely get rid of their symptoms. However, in the treatment of facial pain caused by fibromyalgia, sphenopalatine ganglion block is no more effective than placebo. As a whole, pain relief from sphenopalatine ganglion block may be only temporary for some patients, and the effectiveness and duration of relief varies. A nerve block may result in years of pain relief, or only weeks. On the positive side, this is a low risk, minimally invasive treatment that may be successful in pain relief.
Elizabeth Cudilo M.D., Paul Lynch M.D., and Tory McJunkin M.D. Sphenopalatine Ganglion Block. Retrieved from http://arizonapain.com/pain-center/pain-treatments/sphenopalatine-ganglion-block/
WebMD. (February 12, 2012). Pain Management and Nerve Blocks. Retrieved from http://www.webmd.com/pain-management/guide/nerve-blocks
Cedars-Sinai. (2012). Sphenopalatine Blocks. Retrieved from http://www.cedars-sinai.edu/Patients/Programs-and-Services/Pain-Center/Head-and-Neck-Pain/Sphenopalatine-Blocks.aspx